Varicella complications in children one-site Polish population – a 19- year long survey.

Objectives: The aim of this study was to describe the epidemiology of chickenpox complications in children, based on a 19-year long survey.

Methods: This publication constitutes a review of medical records of 761 patients under the age of 18 who were hospitalized at the T. Browicz Provincial Hospital for Infectious Diseases in Bydgoszcz, Poland from the 1st of January 1999 to the 31st of December 2017.

Results: Over the study period, 761 children diagnosed with varicella complications were hospitalized. The mean number of hospitalizations in each year amounted to 40. The median age of admitted patients was 4 years. The median length of hospitalization was 5 days (ranged from 1 to 30 days). The most frequent varicella complications included respiratory tract infections – 229/761 (30.1%), bacterial skin infections – 189/761 (24.8%) and gastrointestinal tract disorders – 142/761 (18.6%). Pneumonia, bronchitis and gastrointestinal tract disturbances, were reported most often in children under 2 years of age, while neurological complications occurred most frequently in children at 3-6 years of age. No significant differences in the number of varicella complications between immunocompromised and immunocompetent children were reported.

Conclusions: Varicella complications mainly affect the youngest immunocompetent children. Population-wide vaccination and herd immunity appears to be the best way to reduce the incidence of chickenpox and the rate of varicella complications. This study gives support for inclusion of universal varicella vaccine in the National Immunization Program in Poland.